[Shovah32]

Using undead to get control of your waters will leave you with a very defendable position, your main goals imo should be:
1)Conquer the island, not wasting magical resources on making anything you cant get over the water.
2)Conquer the water round the island, recruiting many independants to defend it
3)Get a beach-head on the mainland and get some forts out to protect your labs, the island can still be the main research center for safety against flying and stealthy raiders.
4)While doing all this watch out incase you meet rlyeh, if you expect to do so start spamming temples
5)Give most of your gems and money to pangaea for giving you this plan